Unless otherwise stated, \(\Re \left\lbrace  x\right\rbrace  \)  and \(\Im \left\lbrace  x\right\rbrace  \)  represent the real and imaginary part of \(x\) ,
operators \(E\left[\cdot \right]\)  and \(\left|\cdot \right|\)  denote the statistical expectation and the absolute value, respectively, while the operator \(\exp \left(\cdot \right)\)  denotes the exponential function.
The operator \(\operatorname{card}\left(\mathcal {A}\right)\)  returns the cardinality of the set \(\mathcal {A}\) .
The lower [1]} and upper incomplete Gamma functions [1]} are represented by \(\gamma \left(\cdot ,\cdot \right)\)  and \(\Gamma \left(\cdot ,\cdot \right)\) , respectively, while the Gamma function [1]} is denoted by \(\Gamma \left(\cdot \right)\) .
Finally, \(\Gamma \left(\cdot ,\cdot ,\cdot ,\cdot \right)\)  is the extended incomplete Gamma function defined in [4]}.
